Electron-discharge device



1 2 May 9 7 A. MAVROGENIS ELECTRON DISCHARGE DEVICE Filed Sept. 16. 1926 2 Sheets-Sheet l INVENTOR firm/ 0$ fizw 27/3 ATTZORNEYS May 17, 1927.

A. MAVROGENIS ELECTRON DISCHARGE DEVICE Filed Sept. 16 1926 2 Sheets-Sheet 2 d/ro 527/3 INVENTOR 4/ 1 a /J// A'YlEYS Patented May 17, 1927.

PATENT OFFICE.

ARISTOTI IA'VBOGENIB, OI MILWAUKEE, WISCONSIN.

ELECTRON-DISCHARGE DEVICE.

Application med September 16, 1928. Serial 110. 135,817.

electron disuai'y 2, 192

urther objects of this invention are to provide a novel form of electron discharge device combining as a' unitary member a full wave rectifier, a current limiting device and an audion, and so constructed that the condenser used as storage condenser can be materially reduced in mm with consequent reduction in cost and reduction in the size of the device itself, if need be, or else to provide for the material increase in output of the device.

Further objects are to provide a device having the characteristics enumerated above which is adapted to be directly connected to the usual alternating current lighting circuits so that it will be supplied directly from the circuits without the intervention of a step-up or step-down transformer and without the use of a resistance bridged across the mains to furnish the usual neutral point.

It is the usual ractice in full wave rectification to provi' e' a transformer in whic .the neutral point is furnished by means of the center point of the secondary, to rovide a resistance connected across mains and to locate the neutral point at the center point of the resistance.

Both of the schemes noted above result in an increasein the cost of a device and require aux'iliary'apparatus. For example. ii'the resistance is placed in the tube itself it markedly interferes with the operation of the elements of the tube, due to the heat liberated in the tube. Further the volta e drop jis necessarily high through the evice and through the resistance with conuent loss in powerand efiiciency.

is invention is designed to overcome the defects enumerated above, and other objects of this invention are to so construct the electron dischar e device that itmay be directly eonnecte to the alternating current or else the mains without employing either a transformer or a resistance and without increasmg the cost of the device. An embodiment of the invention is shown in the accompanying drawings, in which:

F1gure 1 is an enlarged v1ew of the tube with parts broken away for clearness.

Figure 2 is a transverse sectional view approximately on the line 2-2 of Figure 1.

Figure 3 is a sectional view approximately on the line 3-3 of Figure 1, showing the condenser with parts broken away.

Flgure 4 is a fragmentar view of the cathodes and, filament, suc view being partly in section.

Figure 5 is a diagrammatic view showing one form of the tube connected in a circuit. Figure 6 is a similar. view showing a slightly modified form of tube. eferring to the drawings, particularly Figures 5 and 6, it will be seen that the tube comprises a main evacuated vessel 1 carried by a base 2. In the diagram the upper portion is to be understood as the evacuated space and the lower portion as the base. This construction is more clearl indicated in Figure 1, from which it wil be seen that the tube body 1 is of the usual contour on its outer side and the base 2 is substantially like the conventional type of vacuum tube base.

The tube is provided with a filament 3 which is connected to the prongs 4 and 5 h of the tube and from thence through a variable resistance 6 to the alternating current mains 7 and 8.

The filament heats the cathode 9 of the full wave rectifier, the cathode 10 of the current limiting device, and the cathode 11 of the audion.

It is to be noted that the anodes 12 and 13 of the full wave rectifier are connected to opposite ends of the filament within the tube and are thus connected to the prongs 4 and 5. v

Further .it is to be noted that-the anode 14 of the current limiting device is connected to the cathode 9 of the rectifier and the cathode 10 of the current limiting device is connected to the plate or anode 15 of the audion, the grid 16 being interposed between the plate 15 and the cathode 11. It is to be noted-that thegrid 16 is provided with a prong 17 and that the catho e 11 is similarly provided with a prong 18. Further, it is to be noted that a fifth prong 19 is connected to the middle point of the filament and is connected through the out-put circuit consisting of a primary 20 to the cathode 11. Further, it is to be noted that the grid is connected to the cathode 11 of the audion through thesecondary 21 of the in-put transformer.

It is to be particularly noted that a storage condenser "22 is connected between the oathode 9 of the rectifier and the center point of the filament 3. Further, a bypass condenser 23 .is connected between this center point of the'filament and the anode or plate 15 of the audion. These connections are made within the tube or within the tube base, in actual practice.

In operation it will be seen that the three cathodes namely 9, 10, and 11, of the rectifier, current limiting device and the audion, are heated by the filament. Further it is to be noted that the anodes 12 and 13 of the rectifier are connected to the mains 8 and 7 respectively. p

Considering for an instant the condition when the main 8 is positive and the main 7 negative, it will be seen that current passes from the anode 12 of the rectifier to its cathode 9. From thence it passes to the anode 14 of the current limiting device, and from the cathode 10 of the current limiting device it passes to the plate 15 of the audion. From this point current passes to the cathode 11 of the audion through the primary 20 and to the middle or neutral point of the filament.

It is to be noted that the condenser 22 acts as a storage condenser as it is connected between the cathode 9 of the rectifier and the centefipoint of the filament, and consequently is charged and gives up a portion of its charge during each half cycle. Further, considering the condition when the main 7 is positive and the main 8 negative. In this case current passes from the anode 13 of the rectifier to the cathode 9 thereof and from thence follows the circuit previously traced. Consequently the condenser 22 is again charged during the half cycle. The current limiting device, however, at all times holds the current value to a predetermined point so that no fluctuation can occur in the current delivered from the current limiting device. However, it is to be noted that the storage condenser 22 may be made very much smaller than in my previously mentioned invention, as the rectifier is 'a double wave rectifier. Further it is to be noted that no transformer is required with this type of tube as the connections are such that the center point of the filament is utilized as the neutral point.

It is to be noted further that the bypass condenser 23al1 ws f r var t on in h current flow through the audion as the current flowing through this portion of the device depends upon the incoming signals.

It will e seen that the condensers 22 and 23- have a common point and consequently may be built up as a single block, as indicated at 24 in Figure 1, the common point of the condensers being connected to the prong 19.

It will be seen further that this device provides for the use of a very much smaller storage condenser than has heretofore been possible, and further that the filament operates in a dual capacity, namely, to heat the various cathodes and at the same time to furnish a neutral point for the return of the audion current.

In the form shown in Figure 6 the tube and base are identically the same as in Figure 5 and the circuits are the same, exceptfor the fact that the by-pass condenser 23 is bridged by the by-pass resistance 25. This resistance acts in conjunction with the condenser 23 and bypasses a portion of the current supplied the audion to thus further provide for fluctuation in the current passing through the audion in accordance with the received wireless waves.

It is to be noted that the temperature of the filament is controlled by the variable resistance 6 and further it is to be noted that the voltage impressed upon the plates of the apparatus is simultaneously controlled by this resistance. Thus the control of the tube is reduced to a single element.

The actual construction of the tube is indicated in Figures 1, 2, 3, and 4. It will be seen that the tube 1 is provided with a reduced neck 26 which fits within the base 2 and is cemented therein in-the usual manner. Preferably immediately below the neck 26 of the tube a mica washer 27 is positioned to prevent the cement from finding its way into the lower portion of the base. Within this lower portion of the base the condenser block 24 is positioned, such condenser block including, as stated above, the condensers 22 and 23. I

The construction of the heater is indicated in Figure 1, from which it will be seen that the filament 3 is carried within porcelain or quartz tubes 28 and has connections at its center and terminal points. The quartz tubes 28 are arranged in a substantially V-shape. They are surrounded at their upper ends by metal tubes, such as tungsten tubes, for instance, which constitute the cathode 11 of the audion. At its lower ends it is surrounded by metal tubes, such for instance as tungsten, which constitute the cathode 10 of the device and the cathode 9 of the rectifier.

The plate 15 of the audion is preferably carried in the upper portion of the app ratus by means of suitable supports, as

current limiting ure 1.)

shown in Figure 1, and the grid 16 is positioned within this encircling plate and carried preferably by the supports indicated at 29 in Figure 1. In order to space the side strands of the grid from the cathode of the audion, preferably an additional rod 30 'is secured to each of the supports 29, as

shown in Figure 1. The center oint of the filament is connected to the mem r 31, (see Figure 1) and from thence by means of a suitable support to the prong 19.

The plates 12 and 13 of the rectifier are carried by suitable su ports and are held in spaced relation to t e cathode 9 to such rectifier. The plate 14 of the current limiting device is preferably U-shaped and is carried by a forked support 32, (see Fighis support is connected by means of the conductor or 'bar 33 to the cathode 9 of the rectifier.

The supports are all sealed within a glass bridge iece 34 which extends downwardly and 1s oined at the base of the tube to the engelop or enclosing body portion of the tu c.

It will be seen that a very effective and compact device has been provided b' this invention, in which relatively smal condensers ma be em loyed and are carried within the ase of t e tube so that the tube forms a unitary device complete in itself.

Further, it will be seen that the tube may be constructed with scarcely any greater ex ense than the usual types of vacuum tu e, although it embodies means fordirect connection to commercial alternating current lighting mains and does not require the .use of a condenser, a resistance, choke coils, or other auxiliary apparatus.

It is to be noted further that even if the tube is connected to a direct current, commercial, or ordinary lighting main, it will still function in a satisfactory manner, as one or the other of the plates 12 or 13 of the rectifier will be connected to the positive main, and, consequently, correct operation of the tube will result.

It will thus be seen that the tube is capable of universal use with either type of supply main, and, as stated, does not require the use of auxiliary apparatus of any nature.

It is to be noted that the rectifier current flows alternately through opposite halves ofthe heater and, consequently, adds its minute heating effect to the heater so that no waste occurs. This effect, however, 1s so small and is so rapid that there is no appreciable 0r noticeable result from such rectified current flow through the heater. In addition to this, the mass of the several cathodesand of the insulating tube maintains a constant and even temperature.

Although the invention has been described in considerable detail, such description is incomprising an evacuated vessel tendedas illustrative rather than limitin as the invention may be variously embodie and as the scope of such invention is to be determined as claimed.

I claim:

1. unitary electron discharge device comprising an evacuated vessel having a full wave rectifier provided with a pair of plates and a cathode, a current limiting device provided with a plate and a cathode, the plate of the current limiting device bein connected to the cathode of the rectifier, an an audion having a plate and a cathode and an interposed grid, the plate of the audion being connected to the cathode of the current limitin device, a heater for said cathodes, and a connection leading to the center point of the heater.

2. A unitary electron dischar e device aving a full wave rectifier rovided with a pair of plates and a catho e, a current limitin device rovided with a plate and a catl iode, the p ate of the current limiting device being connected to the cathode'of the rectifier, and an audion having a plate and acathode and an interposed grid, the plate of the audion being connected to the cathode of the current limiting device, a heater for said cathodes, and a connection leading to the center point of the heater, the plates of the rectifier being connected to opposite ends of said heater.

' 3. A unitary electron discharge device comprising an evacuated vessel enclosing a rectifier, a current limiting device and an audion, said rectifier having a cathode and a pair of plates, said current limiting device havin a cathode, and a plate connected to t e cathode of the rectifier, said audion having a cathode, a grid and a plate with the plate connected to the cathode of the current limiting device, a heater for said cathodes, and a storage condenser connected between the center point of the heater and the cathode of the rectifier, the plates of said rectifier being connected to the ends of said heater.

4.. A unitary electron discharge device comprising an evacuated vessel enclosing a rectifier, a current limiting device and an audion, said rectifier having a cathode and a pair of plates, said current limiting device having a cathode and a plate connected to the cathode of the rectifier, said audion-having a cathode and a plate and a rid with the plate connected to the catho e of the current limiting device, a heater for said cathodes, and a storage condenser connected between the center point of the heater and the cathode of the rectifier, the plates of said rectifier bein connected to the ends of said'heater, said device having five prongs, two of the prongs being connected to the terminals of the heater and the plates of the rectifier, one of said prongs being connected to the center point of the heater, one of said prongs being connected to the cathode of the audion, and the remaining prong being connected to the grid of 'the audion, whereby the grid and cathode of the audion may be connected to an input circuit, and the cathode of the audion and the center point of the heater may be connected to an output circuit.

5. A unitary electron discharge device vcomprising an evacuated vessel having afull wave rectifier'proi'ided with a. pair of plates and a cathode, a current limiting device provided with a plate and a cathode,

the plate of the current limiting device be ing connected to the-cathode of the rectifier,

and an audion having a plate and a cathode.

and an interposed grid, the plate of the audion being connected to the cathode of the current limiting device, a heater for said cathodes, and a connection leading to the centerpoint of the heater, the plates of the rectifier being connected to opposite ends of said heater,. and a bypass condenser between the plate of the audion and the center point of the heater.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of Wisconsin.

ARISTOTE MAVROGENIS. 

